Method and its apparatus for inspecting particles or defects of a semiconductor device

Abstract

An apparatus for optically inspecting particles and/or defects correlates sizes of particles and/or defects to a cause of failure in an inspection result. A data processing circuit points out a cause of failure from the statistics on the inspection result, and displays information on the inspection result. A failure analysis is conducted by setting a threshold for identifying a failure in each of regions on a semiconductor device or the like to statistically evaluate detected particles.

1. An apparatus for inspecting particles and/or pattern defects of en object under inspection, the apparatus comprising:
 illuminating means for irradiating the object under inspection with light;  
 light detecting means for detecting reflected light and scattered light from the object under inspection caused by irradiation of the light by said illuminating means;  
 detecting means for processing signals obtained by detection of the reflected light and the scattered light by said light detecting means to detect particles and/or pattern defects;  
 data processing means for obtaining sizes of the particles and/or the pattern defects and occurrence frequencies of said sizes, based on information on the particles end/or the pattern defects detected by said detecting means;  
 outputting means for outputting information on said sizes and said occurrence frequencies for each size of the particles and/or the pattern defects obtained by said data processing means; and  
 display means for displaying the information from said outputting means,  
 wherein, when a signal outputted from said detecting means is saturated, said data processing means calculates a peak level of said signal using an assumption that said signal is not saturated.  
 
   
   
     2. The inspection apparatus according to  claim 1 , wherein said display means displays on a display screen information on a cause of failure associated with the information on the sizes of particles and/or the pattern defects. 
   
   
     3. The inspection apparatus according to  claim 1 , wherein said display means displays on a display screen information on the particles and/or the pattern defects of a given range of size in a manner discriminative from information on the particles and/or the pattern defects of another range of size. 
   
   
     4. The inspection apparatus according to  claim 1 , wherein said data processing means calculates a yield impact of the particles and/or the pattern defects on a yield, based on information obtained by electrical inspection of the object under inspection, indicating whether the object under inspection is defective or non-defective and information on the sizes of the particles and/or the pattern defects obtained by said data processing means and then causes said display means to display on a display screen a result of calculation of the degree of the yield impact. 
   
   
     5. An apparatus for inspecting particles and/or pattern defects of an object under inspection, the apparatus comprising:
 illuminating means for irradiating the object under inspection with light;  
 light detecting means for detecting at least one of reflected light and scattered light from the object under inspection caused by irradiation of the light by said illuminating means;  
 detecting means for processing signals obtained by detection of said at least one of the reflected light and the scattered light by said light detecting means to detect particles and/or pattern defects;  
 data processing means for categorizing the particles and/or the pattern defects into categories that are the particles and the pattern defects; and  
 display means for displaying information on occurrence frequencies of the particles and/or the pattern defects categorized by said data processing means for each of the categories,  
 wherein, when a signal outputted from said detecting means is saturated, said data processing means calculates a peak level of said signal using an assumption that said signal is not saturated.  
 
   
   
     6. The inspection apparatus according to  claim 5 , wherein said data processing means classifies the information on the occurrence frequencies of the particles and/or the pattern defects categorized by said data processing means, according to sizes of the particles and/or the pattern defects and then obtains occurrence frequencies of the particles and/or the pattern detects on a size-by-size basis, and wherein said display means displays information on the occurrence frequencies of the particles and/or the pattern defects on the size-by-size basis obtained. 
   
   
     7. The inspection apparatus according to  claim 5 , wherein said display means classifies information on an occurrence frequency distribution of the particles and/or the pattern defects on the object under inspection according to the categories of the particles and/or the pattern defects, and displays the classified information on the display screen. 
   
   
     8. A method of inspecting particles and/or pattern defects of an object under inspection, the method comprising:
 irradiating the object under inspection with light;  
 detecting reflected light and scattered light from the object under inspection caused by irradiation of the light;  
 processing signals obtained by detection of the reflected light and the scattered light to detect particles or pattern defects;  
 obtaining sizes of the particles and/or the pattern defects and obtaining occurrence frequencies of said sizes, based on information on the particles and/or the pattern defects detected; and  
 outputting information on said sizes and said occurrence frequencies for each size of the particles and/or the pattern defects,  
 wherein, when a signal outputted from said detecting is saturated, said obtaining calculates a peak level of said signal using an assumption that said signal is not saturated.  
 
   
   
     9. The method of inspecting particles and/or defects according to  claim 8 , comprising:
 displaying on a display screen information on a cause of failure associated with the information on the sizes of the particles and/or the pattern defects.  
 
   
   
     10. The method of inspecting particles or pattern defects according to  claim 8 , comprising:
 displaying on a display screen information on the particles and/or the pattern defects of a given range of size in a manner discriminative from information on the particles and/or the pattern defects of another range of size.  
 
   
   
     11. The method of inspecting particles and/or pattern defects according to  claim 8 , comprising:
 calculating a yield impact of the particles and/or the pattern defects on a yield, based on information obtained by electrical inspection of the object under inspection, indicating whether the object under inspection is defective or non-detective and information on the sizes of the particles and/or the pattern defects obtained, and then displaying on a display screen a result of calculation of the degree of the yield impact.  
 
   
   
     12. A method of inspecting particles and/or pattern defects of an object under inspection, the method comprising:
 irradiating the object under inspection with light;  
 detecting at least one or reflected light and scattered light from the object under inspection caused by irradiation of the light;  
 processing signals obtained by detection of said at least one of the reflected light and the scattered light to detect particles and/or pattern defects;  
 categorizing the particles and/or the pattern defects into categories that are particles and pattern defects; and  
 displaying on a display screen information on occurrence frequencies of the particles and/or the pattern defects categorized, for each of the categories,  
 wherein, when a signal outputted from said detecting is saturated, said categorizing calculates a peak level of said signal using an assumption that said signal is not saturated.  
 
   
   
     13. The inspection method according to  claim 12 , comprising:
 classifying the information on the occurrence frequencies at the particles and/or the pattern defects categorized, according to sizes of the particles and/or the pattern defects, obtaining occurrence frequencies of the particles and/or the pattern defects on a size-by-size basis, and then displaying on the display screen information on the occurrence frequencies of the particles and/or the pattern defects on the size-by-size basis obtained.  
 
   
   
     14. The inspection method according to  claim 12 , comprising:
 classifying information on an occurrence frequency distribution of the particles and/or the pattern defects on the abject under inspection according to the categories of the particles and/or the pattern defects, and then displaying the information classified on the display screen.  
 
   
   
     15. An apparatus for inspecting particles and/or pattern defects of an object under inspection, the apparatus comprising:
 illuminating means for irradiating the object under inspection with light;  
 light detecting means for detecting reflected light and scattered light from the object under inspection caused by irradiation of the light by said illuminating means;  
 detecting means for processing signals obtained by detection of the reflected light and the scattered light by said light detecting means to detect particles and/or pattern detects;  
 data processing means for obtaining sizes of the particles and/or the pattern defects and occurrence frequencies of said sizes, based on information on the particles and/or the pattern defects detected by said detecting means;  
 outputting means for outputting information on said sizes and said occurrence frequencies for each size of the particles and/or the pattern defects obtained by said data processing means; and  
 display means for displaying the information from said outputting means,  
 wherein, when a signal outputted from said detecting means is saturated, said data processing means uses saturated signal waveform data therefrom, to calculate an estimated peak level of said signal.  
 
   
   
     16. The inspection apparatus according to  claim 15 , wherein said data processing means uses Gaussian distribution analysis of said saturated signal waveform data to calculate the estimated peak level of said signal. 
   
   
     17. The inspection apparatus according to  claim 16 , wherein said data processing means uses simultaneous Gaussian equation analysis of said saturated signal waveform data to calculate the estimated peak level of said signal. 
   
   
     18. The inspection apparatus according to  claim 16 , wherein said data processing means uses Gaussian distribution approximation to calculate the estimated peak level of said signal. 
   
   
     19. A method of inspecting particles and/or pattern defects of an object under inspection, the method comprising:
 irradiating the object under inspection with light;  
 detecting reflected light and scattered light from the object under inspection caused by irradiation of the light;  
 processing signals obtained by detection of the reflected light and the scattered light to detect particles or pattern defects;  
 obtaining sizes of the particles and/or the pattern defects and obtaining occurrence frequencies of said sizes, based on information on the particles and/or the pattern defects detected; and  
 outputting information on said sizes and said occurrence frequencies for each size of the particles and/or the pattern defects,  
 wherein, when a signal outputted from said detecting is saturated, said obtaining uses saturated signal waveform data therefrom, to calculate an estimated peak level of said signal.  
 
   
   
     20. The method of inspecting particles and/or defects according to  claim 19 , wherein said obtaining uses Gaussian distribution analysis of said saturated signal waveform data to calculate the estimated peak level of said signal. 
   
   
     21. The inspection apparatus according to  claim 20 , wherein said data processing means uses simultaneous Gaussian equation analysis of said saturated signal waveform data to calculate the estimated peak level of said signal. 
   
   
     22. The inspection apparatus according to  claim 20 , wherein said data processing means uses Gaussian distribution approximation to calculate the estimated peak level of said signal.